In recent years, with the progress of science and technology, the liquid crystal display has the advantages of power saving, no radiation, small size, low power consumption, flat right angle, high resolution, stable image quality and the like, and is especially suitable for various types of information products such as: a Mobile phone, a notebook computer, a digital cameras, a PDA, a liquid crystal display screen and the like are more and more popular, so that the demand of the liquid crystal display (LCD) is greatly increased.
At present, the liquid crystal displays widely used are generally provided with two substrates and a liquid crystal layer is interposed between the two substrates, and a sealing member is positioned between the two substrates in the peripheral region so as to bond the two substrates together, and the liquid crystal layer is hermetically sealed between the two substrates.
In order to enable liquid crystal molecules between two substrates to form a certain pre-tilt orientation, an alignment layer or an orientation layer needs to be formed on the surfaces of the two substrates respectively. In general, the alignment layer further includes a rubbing step performed by rubbing the surface of the alignment layer with a rubbing roller to form the tiny groove for pre-tilt the liquid crystal molecules. After the formation of the alignment layer with the pre-tilt orientation groove is completed, the sealing member is used to bond the two substrates together.
In an existing display panel, a plurality of photo spaced retaining walls and a plurality of grooves are arranged in the peripheral area of the substrate so as to prevent the alignment layer forming solution (e.g., polyimide (PI) solution) from being coated on the non-effective display area of the color filter substrate, and are used to guide the overflowing of alignment layer forming solution flow back to the effective display area.
However, the design of the existing photo spaced retaining walls is mostly in parallel and with the same height, this design is likely to cause the poor fluidity of the alignment layer forming solution. And when the accumulation of the alignment layer forming solution is too large, a portion of photo spaced retaining walls will have the alignment layer forming solution residue. The residues may cause the cell gap of the display panel to be slightly higher in the peripheral region, and the display panel will have the border white, brightness uneven, residual and other bad phenomena as so called “mura”.
In addition, in the four corners of the periphery of the sealing member bonded substrates there are no special designs for guiding the alignment layer forming solution, therefore there will be a case where the effluent is accumulating during the production process. Due to the four corners of the bonded substrates have the problem of the volume of the alignment layer forming solution accumulated increasingly, therefore the cell gap of the display panel near the four corners has problem prone to abnormal heighten.